EEDI / EEXI /CII THE NEW NORMAL

Overview

The shipping industry is engaged in a considerable challenge to decarbonize operations significantly within the next decade as part of global energy transformation. 

The initial IMO GHG Strategy aims to reduce the carbon intensity of international shipping by 40% by 2030 (considering 2008 as baseline) and pursue efforts to achieve a 70% reduction by 2050.  

It also aims to reduce total annual GHG emissions from international shipping by at least 50% by 2050 compared to the 2008 baseline. 

To achieve the goal of reducing carbon intensity by 70% compared with 2008, a mix of design, technical, operational measures and innovative measures is required. 

In summary, the latest changes include technical requirements for existing vessels and operational requirements for all vessels with the aim of reducing their carbon intensity.

The short-term measures to reduce GHG emissions from ships have been adopted as amendments to MARPOL Annex VI with entry into force on 1 November 2022. They include technical measures;

• Calculation and verification of the Energy Efficiency Index for existing ships (EEXI); 

and operational requirements/measures;

• Introduction of a rating mechanism linked to the operational carbon intensity indicators (CII)
• Improved Ship Energy Efficiency Management Plan (SEEMP) to include targets for operational emissions

with the requirements for EEXI and CII certification coming into effect from 1 January 2023.

For a new design, the marine industry has been used to the requirements given in the Energy Efficiency Design index (EEDI), which foresee gradual improvements in energy efficient ship design and building. The principle has been extended to cover existing ships through the Energy Efficiency existing ship Index (EEXI). It is now to be combined with an operational approach through the operational carbon intensity reduction factor (CII) and regulated through enhanced use and auditing of the Ship Energy Efficiency Management Plan (SEEMP).

As the discussions on GHG strategy are still ongoing, it is expected that IMO will revise it and take a number of steps in the near future. One of the steps are updated guidelines which are to be released shortly: 

• Guidelines adopted at MEPC 76 for the EEXI calculation, associated survey, certification, and shaft-engine power limitation; 
• Guidelines adopted at the MEPC 76 for the calculation and certification of the Carbon Intensity Indicator (CII) 

New ships - Energy Efficiency Design Index (EEDI) 

The Energy Efficiency Design Index (EEDI) is now a well-known parameter for all maritime operators and recognized as the most important technical measure for energy efficiency in new ships. Aiming to ensure that new ships are designed to be energy efficient, it indicates the number of grams of CO2 emissions per capacity mile (e.g., tonne mile). This index represents only technical design aspects such as the optimization of engines, hull and propeller or the use of non-fossil fuels; it does not cover operational or commercial aspects. The calculation takes into account different ship types and size segments. The EEDI has a constant value, which will only be changed in the event of ship modifications.

For each new ship, the EEDI attained must be equal to or lower than the required EEDI. Following the amended requirements outlined in MEPC 254 (67), the EEDI calculation and associated technical documentation must be approved during the design stage and confirmed during sea trials through the completion of the initial survey. The ship’s International Energy Efficiency Certificate (IEEC) can then be issued. 

Existing ships - Energy Efficiency Index (EEXI)

Like the EEDI, the EEXI is a mandatory measure with a goal-based objective. It offers a number of options to improve energy efficiency and addresses this issue on all vessels regardless of differences in design, function and size. The EEXI scheme is based on the same type, size and category of ships used for the EEDI requirements.

Bulk carrier, Gas carrier, Tanker, Containership, General cargo ship, Refrigerated cargo carrier, Combination carrier, Ro-ro cargo ship, Ro-ro cargo ship (vehicle carrier), Ro-ro passenger ship, LNG carrier having conventional propulsion, and cruise passenger ship and LNG carrier having non-conventional propulsion (i.e. diesel-electric propulsion, turbine propulsion, hybrid propulsion systems, etc.) of 400 GT and above engaged in international voyages shall calculate the Attained EEXI. Required EEXI will be calculated for each ship as per the vessel type and size basis MARPOL Annex VI, Regulation 19-21 and MEPC 75 / MEPC 76 guidelines. The attained EEDI/EEXI should be less than the required EEXI, calculated as:

Required EEXI = (1-Y/100) × EEDI Reference line value

Where Y is the reduction factor specific for each ship type.

For those ships already having a verified attained EEDI, this value may be taken as the Attained EEXI if it is equal to or less than the required EEXI. In this case, the Attained EEXI shall be verified based on the EEDI Technical File. 

If the attained EEXI does not comply with the requirement, a solution must be found to raise the efficiency index to the required level. Therefore, it is important to clarify parameters that are sensitive for this calculation; 

• Main Engine Power 
• Auxiliary Power 
• Fuel consumption 
• Reference speed Vref 
• Ship Capacity 

The EEXI framework also makes this possible for other efficiency improvements such as fuel change and/or energy saving devices. 

One option to improve EEXI attained is to install energy- efficiency technologies to increase the reference speed for constant installed power. Energy-Saving Devices (ESDs) may be beneficial in cases where the EEXI has been exceeded only slightly and when more complex retrofits of hull/ machinery may offer greater benefits. A CFD calculation may be used to document the ship-specific effect of an ESD in the EEXI calculation and the technical file. Solutions may be based on: 

• Wind Assisted Propulsion (WAP) - Fitting of sails or other technology utilising wind power on deck to assist in the propulsion of the vessel 
• Increased propeller efficiency - Various methods to enhance propeller efficiency by optimising water flow around the propeller; advance rudder and propeller, speed nozzle, etc. 
• Alternative fuel - Switch to carbon-neutral or carbon-free fuel; LNG / CNG / LPG carbon capture; Bio-Methane; “Green” Methanol; “Green” Hydrogen 
• Improved hull paints - Applying the correct paint on the correct hull area to reduce frictional resistance of the ship.
• Solar-sail system - Innovative renewable energy solution for powering and controlling ship’s electrical equipment, including marine solar panel array, battery pack, charge controllers, marine computer plus associated communications and interface devices.
• Optimised cooling system – Upgrading of cooling water system's pipes, coolers and pumps to decrease resistance to the flow. 
• Air bubbles hull lubrication - Supplying air to the ship’s underside in order to create a layer of tiny bubbles that would help in reducing the friction between the hull and the seawater
• Fuel and Solar Cell Propulsion - The fuel cell propulsion utilises power from a combination of fuel cells, solar cells and battery systems helping in reduction of GHG emissions.
• Exhaust scrubber - Exhaust gas cleaning technology scrubs Sulphur oxides (SOx) from the ship´s engine and boiler exhaust gases and reduces emissions emitted from vessels.

The final EEXI technical file (and SEEMP) are to be submitted to Class for review, and a verification survey must be carried out prior to issuance of a new IEE certificate. The verification of the ship's Attained EEXI shall take place at the first annual, intermediate or renewal survey of the IAPP Certificate or the initial survey of the IEEC Certificate, whichever is the first, on or after 1 January 2023.

Annual operational Carbon Intensity Indicator (CII) 

The attained annual operational CII of an individual ship (applicable to all ships above 5,000 GT) is calculated as the ratio of the total mass of CO2 (M) emitted, to the total transport work (W), undertaken in a given calendar year. Calculations will be based on data in the IMO Data Collection System (DCS) to rate each ship according to how its CII relates to an agreed CII reference value, and classify the ship annually in a category (A, B, C, D or E) according to its annual attained CII.

Based on different understandings of “transport work”, IMO is considering two calculation methods for the attained CII: 

• Annual Efficiency Ratio (AER) based on IMO DCS data; or 
• Energy Efficiency Operational Index (EEOI).

The AER represents a supply- based approach while the EEOI represents a demand- based approach.

IMO DCS reported data enables the calculation of a carbon intensity metric known as the Annual Efficiency Ratio (AER), using the parameters of the annual total fuel consumption and distance travelled, plus deadweight tonnage (DWT). AER is reported in unit grams of CO2 per tonne-mile (gCO2/dwt-nm).

The Energy Efficiency Operational Indicator (EEOI) is a carbon intensity metric similar to the AER. The difference is that capacity is expressed as actual cargo carried for each voyage. To ensure they are completely defined, ballast voyages should be attached to related cargo voyages and EEOI calculated for the complete round trip. In order to work as an annual indicator, EEOI has to be calculated for each round-trip voyage and the rolling average for the year must be calculated and reported. The unit of EEOI depends on the measurement of cargo carried or the transport work done, e.g., tons CO2/(tons/ nautical miles), tons CO /(TEU/nautical miles) or tons CO2/(person/nautical miles), etc. The EEOI is compatible with data collected and reported for the EU MRV regulation. 

Operational carbon intensity rating is based on assigning a ranking label from among the five grades (A, B, C, D and E) to the ship, based on the attained annual operational carbon intensity indicator.  Indicating a major superior, minor superior, moderate, minor inferior, or inferior performance level. The middle point of rating level C is the value equivalent to the required annual operational CII set out in the regulations. A ship rated E or rated D for three consecutive years must develop a plan with corrective actions to achieve the required annual operational CII. The SEEMP should include this plan along with corrective actions. 

Several options exist to improve the CII, including changes to both design and operations. For retrofit decisions, vessels and operational profile needs should be evaluated carefully to confirm suitability and financial feasibility. Possible solutions include:

• Waste heat recovery system 
• Air lubrication system (ALS)
• Alternative fuels
• Improved logistics
• Energy saving device (ESD)
• VFD control
• Weather routing
• Wind assisted propulsion system (WAPS)
• LED lighting on board
• Hull cleaning and coating

Ship Energy Efficiency Management Plan (SEEMP) 

The SEEMP scheme is likely to become a tool for managing energy efficiency where ship owners may choose measures to reduce emissions from their vessels. SEEMP should be developed as a ship-specific plan by the company and reflect efforts to improve the ship’s energy efficiency. 

SEEMP shall include:

• Description of the methodology that will be used to calculate the ship's Attained annual operational Carbon Intensity Indicator (CII) and the processes that will be used to report this value to the ship's flag Administration
• Required annual operational CII for the next 3 years
• Implementation plan documenting how the Required annual operational CII will be achieved during the next 3 years
• Procedure for self-evaluation and improvement

Confirmation of compliance shall be provided by the Administration/RO and retained onboard prior to 1 January 2023. The SEEMP shall be subject to verification and Company audits.

EEXI COMPLIANCE PROCESS

(Calculation, improvement implementation, and certification process)

With the proposed implementation of EEXI and CII factors by IMO, it becomes imperative to confirm compliance of each vessel to meet the requirements. 

Step 1. Calculating current EEXI

Calculation of the attained EEXI based on vessel’s particulars (type, size, etc.) as per relevant regulations and guidelines;

Comparison of the calculated EEXI with the required EEXI in 2023.

Step 2. Analysing potential measures (technical and/or operational)

Assessment of options to comply with EEXI requirements;

Comparison of different improvement solutions with respect to investments, future operations and planned service life 

Step 3. Implementation/ Installation of potential measures

Detailed calculations and analysis;

Turn-key installation/Retrofit services;

Commissioning assistance

Step 4. Class verification

Class survey of implemented/installed measures

Step 5. Finalising EEXI technical file

Collecting and compiling all necessary documentation (including the details of EEXI calculations, any additional information such as survey reports, etc.) for preparation of EEXI Technical file 

 Step 6. Class approval of EEXI technical file

Submission of the vessel specific EEXI technical file to the respective classification society

Step 7. On-board survey and issuance of a new IEEC

Approval of the EEXI technical file by the Administration or the Recognized Organization;

IEEC certificate issuance

The Bluestone Group is at your disposal for any clarifications, technical discussions, and review of documentation, enabling you to evaluate the technical challenges specific to your vessel/fleet or business.